Researchers from Arizona State University, with Read on Arizona, wanted to find out which factors might impact a student’s ability to read by third grade. The answer for students in Arizona was clear: good attendance makes a real difference. Read on Arizona is a statewide public and private partnership aimed at boosting language and literacy skills for children from birth through age eight.

“Although this seems intuitive, our analysis suggests that for those looking to improve student learning, particularly as it relates to literacy, increasing attendance rates may be critical first step,” the researchers wrote in a blog post for the Brookings Institution.

The analysis found that for a 1 percent increase in third grade attendance rates, there is an average increase of 1.5 percent of students passing the Arizona Instrument to Measure Standards (AIMS) third grade reading test at the school-level in 2013-2014. Similar results hold for students who miss too much school: For a 1 percent increase in chronic absenteeism (i.e. the percentage of students who miss 18 or more days in a given school year), there is an average decrease of 0.3 percent of students passing third grade AIMS reading, they found.